The health effects aren't nebulous. The effects of this kind of exposure have been studied; see this from the CDC, this, and there are many other studies. Go to Pub Med and search on "world trade center pulmonary" or "world trade center disease" and you'll find peer reviewed articles on this.
Please also be aware that some of those volunteering for searching the rubble, or clean up, were not "signed up for a dangerous job." They were volunteers who turned out to help. Here's the story of some one who died from the effects.
Frequent trips to the ER because you can't breathe are not "riding the leisure train."
My argument is not with the responders, many of whom who are sick and deserve help. My argument is with the Congressional Democrats who cynically roll out this fundamentally flawed bill, over and over again, in order to score cheap political points when the Republicans do the responsible thing and vote it down.
It would be nice if there was bipartisan consensus to kill this bill, which is rife with potential for fraud and abuse, and replace it with a real solution. But the Democrats don’t want to do that. They want to keep both hands on this club, so they can keep beating the Republicans over the head with it.
Meanwhile, the sick responders suffer. They should not hold their breath waiting for the Democrats to solve the problem.